Lubricating oil of high oiliness and resistance to oxidation



Patented Oct. 26, 1937 NITE STATES PATENT OFFICE LUBRICATING OIL OF HIGHOILINESS AND RESISTANCE T OXIDATION I Eugene Lieber, Linden, N. 1.,assignor to seamiard Oil Development Company, a corporation of DelawareNo Drawing.

14 Claim.

The present invention relates to improved lubricating oils, ,especiallyto oils of higher re ment in one respect is detrimental in the other.

In the present instance, a new class of lubricating oil improvers isdisclosed which simultane- .5 ously works an improvement in the oil bothin respect to resistance to oxidation and to its oiliness value.

The particular class of substances which has been discovered at thistime comprises the 'esters and tellurium directly attached to anaromatic ring. Sulphur may be combined with the rings as mercaptan,disulphide or monosulphide, that is to say, thioether is quite efiectivewhen utilized in any of these threeforms. These groups will be includedin the term sulpho-aromatic groups but it will be understood thatequivalents of the sulfur atom are included.

The aromatic ring may be phenolic or of the l0- condensed form such asnaphthalene or anthracene and the alkylated aromatic rings may also beused. Hydroxyl or amino groups may be present on the ring without.detrimentally afiecting the value of the compounds. Often indeed it is35 found to be improved by their presence.

The aromatic-sulpho-radlcal may be present in the alcoholic or theacidic portion of the ester molecule and more than one of these groupsis oftendesirable. The alcoholic portion of the i0 ester may be anaromatic alcohol or phenol or it may be an aliphatic radical containinga substituted sulpho-aromatic group. It may be mo'iiohydric orpolyhydric aswill be illustrated below.

4 The acidic portion of the ester molecule may 15 contain thesulpho-arom'atic group whether or not such a group is a part of the.alcoholic radical. Mono or poly basic acids may be employed.

, In order more explicitly to disclose the type of compounds which fallwithin the class dis- 50 closed above, the following formulae are given,

which contain sulphur or its equivalents, selenium Application August22, 1935, Serial No. 37,302

but it will be understood that these are merely illustrations and are inno way limitative.

T I s-O-ons-oocmmm s-GdocoJn-m The esters are for the most part freelysoluble in lubricating oils, but only relatively small quantitles arenecessary for the present purposes. As

little as .01% is sufficient to greatly reduce the rate of oxidation ofthe oil, but more is usually preferred, say from .5 to 1% or even 2% or5% or more may be desired to obtain the greatest oiliness values. I

Experiment I I I To an SAE 50 hydrocarbon lubricating oil is added .5%of an'acetic acid ester of iii-tertiary butyl diphenol sulphide. Runswere made on. the

oil blank sample which did not contain these /sub tances' and onthejble'nd, using the Mou y machine and 'method as' described on page 47in the National Petroleum Newsof Novemberll, I

oxidation, 'The blendedand unblended samples were subjected toanoxidation test'in which oxy- The -oil;blend wasverystable in respect togen was bubbled through the sample in a con t'inuous circulatory streamat a fixed rate while the sample was held; at 200 C. The rate of oily:

a gen-absorption is determined at 15 minute intervals by notingv thevolume; of the undissolved oxygen. W

I 1 v I Oxidation rataatZOO 0. cc. cl 0, Samples absorbed [15 min.interval [10 I ccusample Blankin LEE-213+?! Blended 30r-3 1-,%,29 a t lThe present' invention is not limited to any theory of the improvingagents nor to any parx ticular agent mentioned in the disclosure, but

only'to the following claims in w hich it is de- '2. An improvedlubricant comprising a lubri eating oil and a' small quantity of anester con,-

, taming a sulphur atom directlyconnected to an aromatic group.

' 8. Animproved lubricant comprising a lubricoating oil and a smallquantity of an ester containing :ai sulphur atom directly connected toan aromatic group and being a'compound'selected' a from the classconsisting of aromatic disulphides, a i

mercaptans and thio-ethers' 4. An improved lubricant comprising amineral lubricating oil' and a small quantity of an estera containing anaromatic-mercapto group.

- 5. An improved lubricant comprising a petro-, I

15 I ester containing an esterified mercapto-phenolic V leum lubricatingoil and a small quantity of an compound.

,6. An improved lubricant comprisinga lubrieating oil and a smallquantity of an ester containing an esterified mercapto-phenol. I I I a"I. An improved lubricant comprising a hy:-

clrocarbon lubricating oil: and a small quantity E P- a ;8.: An'improved lubricant comprising a lubricating oil and a small quantity ofan esterifie disulphide of a phenolic compound. y

9. An improvedlubricantcomprising a disulphide of aphenol. I 10; Animproved lubricant comprising a lubrian aromatic thio-ether group. a 11.Anwimprovedlubricant comprising a lubrieating oilland a small quantityof an esterified' phenolic compound with a thin-ether group. v

a 12; An improved lubricant comprising a lubrieating oil aind'a' smallquantity of an esterifled' phenol containinga thio-ether group'., a I yl 13; An improved lubricant comprising a lubricating oil and a smallquantity of an esterified diphenol thio-ether.

14. An improved lubricant comprising a. lubrieating oil and a smallquantity of esterified alkyl diphenol thio-ether.

EUGENE LIEBER.

lubrieating oil and'a small quantity of an esterified a a of. an estercontaining an aromatic disulphide .cating oil and a'small quantity of anester with I

